How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask ND-TECH Your Own Question
ND-TECH
ND-TECH, CJDR Master Tech
Category: Chrysler
Satisfied Customers: 1410
Experience:  ASE Certified and CJDR Master
26707557
Type Your Chrysler Question Here...
ND-TECH is online now
A new question is answered every 9 seconds

97 sebring: convertible..2.5 V6..I hear the fuel pump run

This answer was rated:

97 sebring jxi convertable 2.5 V6, I hear the fuel pump run for about a second every time i turn on the key but i get no fuel at the engine. The filter and pump were replaced a year ago. The engine was running fine until i replaced the water pump. Now it wont start. I disconnected the line to the fuel rails on top of the engine and get no fuel even while the pump run for that 1 second.

The dealer wants to replace the pump again. They say there's power to it. If so, why does it stop running after that 1 second run every time i turn on the ignition?
The one second run time after turning on the key is to prime to fuel system. If it runs and you are still getting no fuel up at the engine the th pump has most likely failed and can not flow fuel due to the internal regulator being stuck open
Customer: replied 5 years ago.
The pump only runs for the 1 second "primp" time. If the internal regulator is stuck open, why does the pump stop running after the initial 1 second?
Because its a programed PCM strategy to only actuate the fuel pump for a second to prime the system. There is no fuel pressure sensor to let it know what the PSI of the system is
Customer: replied 5 years ago.
If the pump was working correctly, would it keep running with the fuel line disconnected at the engine. Wouldn't i have gas flowing/
Even with a new pump when you cycle the key on it will only run for a second to just build up pressure in the system. SO if the pump was working then you would get fuel up at the fuel rail. If you are not then you have a bad fuel pump
Customer: replied 5 years ago.
How can it build pressure in the system with the line before the rail disconnected? sorry for the persistance, but i'm not looking foreward to removing the fuel tank AGAIN.
Even if you disconnect the line at the rail the pump with still run with you cycle the key on. If it runs but no fuel comes out of the line then you have a bad pump. It cant build pressure in the system with the line disconnect but you will be able to tell if you have fuel flow in the system with it disconnected and the cycle the key on
Customer: replied 5 years ago.

You said th pumpm only runs "a second to prime the system" and that " there is no pressure sensor to let it know what the PSI of the system is".

 

Then you said "it will only run for a second to just build pressure". How's the PCM know when it's built pressure if there is no sensor?

 

Then you said "it can't build pressure if the line is disconnected" . Then why does it stop running? It hasn't built pressure and there is no fuel flowing.

 

Yes the pump does only run one second to prime the fuel system. Which is for a quick pressure build prior to starting. The PCM dosent need to know what the pressure is. It just runs the pump for a second to prime the system. If you have a good fuel pump the it will work. It stops running because the PCM ONLY actuated the fuel pump for a second the shuts it off. Regardless if the pump is good or bad the PCM is still going to run it for second. Regardless if you have the line connected the PCM will run it for a second. The is a programed strategy in the PCM. It stops running because the PCM has a internal clock and timing circuits to check all of this.
Customer: replied 5 years ago.

How does the engine get its fuel when it is running then? Does it pull it from the tank or is there another pump?

After the vehicle is started the fuel pump is then run constantly. This is a completely separate strategy then just cycling the key on. Ok do this. Take the fuel line off and crank the engine over. If fuel comes out then you will need to do a pressure check on it. If no fuel comes out then you will need to replace the pump.
Customer: replied 5 years ago.
OK, I'll give that a try. You're saying the pump should pump fuel while i'm cranking the engine. If t doesn't, it's bad. Correct?
yes that is what i am saying
ND-TECH and other Chrysler Specialists are ready to help you